148 lines
4.8 KiB
Ruby
148 lines
4.8 KiB
Ruby
require "active_support/core_ext/array/extract_options"
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module ActiveModel
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# == Active \Model \Callbacks
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#
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# Provides an interface for any class to have Active Record like callbacks.
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#
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# Like the Active Record methods, the callback chain is aborted as soon as
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# one of the methods throws +:abort+.
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#
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# First, extend ActiveModel::Callbacks from the class you are creating:
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#
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# class MyModel
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# extend ActiveModel::Callbacks
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# end
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#
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# Then define a list of methods that you want callbacks attached to:
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#
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# define_model_callbacks :create, :update
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#
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# This will provide all three standard callbacks (before, around and after)
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# for both the <tt>:create</tt> and <tt>:update</tt> methods. To implement,
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# you need to wrap the methods you want callbacks on in a block so that the
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# callbacks get a chance to fire:
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#
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# def create
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# run_callbacks :create do
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# # Your create action methods here
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# end
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# end
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#
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# Then in your class, you can use the +before_create+, +after_create+ and
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# +around_create+ methods, just as you would in an Active Record model.
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#
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# before_create :action_before_create
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#
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# def action_before_create
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# # Your code here
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# end
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#
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# When defining an around callback remember to yield to the block, otherwise
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# it won't be executed:
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#
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# around_create :log_status
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#
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# def log_status
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# puts 'going to call the block...'
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# yield
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# puts 'block successfully called.'
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# end
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#
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# You can choose to have only specific callbacks by passing a hash to the
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# +define_model_callbacks+ method.
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#
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# define_model_callbacks :create, only: [:after, :before]
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#
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# Would only create the +after_create+ and +before_create+ callback methods in
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# your class.
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module Callbacks
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def self.extended(base) #:nodoc:
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base.class_eval do
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include ActiveSupport::Callbacks
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end
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end
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# define_model_callbacks accepts the same options +define_callbacks+ does,
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# in case you want to overwrite a default. Besides that, it also accepts an
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# <tt>:only</tt> option, where you can choose if you want all types (before,
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# around or after) or just some.
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#
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# define_model_callbacks :initializer, only: :after
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#
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# Note, the <tt>only: <type></tt> hash will apply to all callbacks defined
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# on that method call. To get around this you can call the define_model_callbacks
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# method as many times as you need.
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#
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# define_model_callbacks :create, only: :after
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# define_model_callbacks :update, only: :before
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# define_model_callbacks :destroy, only: :around
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#
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# Would create +after_create+, +before_update+ and +around_destroy+ methods
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# only.
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#
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# You can pass in a class to before_<type>, after_<type> and around_<type>,
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# in which case the callback will call that class's <action>_<type> method
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# passing the object that the callback is being called on.
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#
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# class MyModel
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# extend ActiveModel::Callbacks
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# define_model_callbacks :create
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#
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# before_create AnotherClass
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# end
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#
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# class AnotherClass
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# def self.before_create( obj )
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# # obj is the MyModel instance that the callback is being called on
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# end
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# end
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#
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# NOTE: +method_name+ passed to `define_model_callbacks` must not end with
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# `!`, `?` or `=`.
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def define_model_callbacks(*callbacks)
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options = callbacks.extract_options!
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options = {
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skip_after_callbacks_if_terminated: true,
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scope: [:kind, :name],
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only: [:before, :around, :after]
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}.merge!(options)
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types = Array(options.delete(:only))
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callbacks.each do |callback|
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define_callbacks(callback, options)
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types.each do |type|
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send("_define_#{type}_model_callback", self, callback)
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end
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end
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end
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private
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def _define_before_model_callback(klass, callback)
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klass.define_singleton_method("before_#{callback}") do |*args, &block|
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set_callback(:"#{callback}", :before, *args, &block)
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end
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end
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def _define_around_model_callback(klass, callback)
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klass.define_singleton_method("around_#{callback}") do |*args, &block|
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set_callback(:"#{callback}", :around, *args, &block)
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end
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end
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def _define_after_model_callback(klass, callback)
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klass.define_singleton_method("after_#{callback}") do |*args, &block|
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options = args.extract_options!
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options[:prepend] = true
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conditional = ActiveSupport::Callbacks::Conditionals::Value.new { |v|
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v != false
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}
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options[:if] = Array(options[:if]) << conditional
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set_callback(:"#{callback}", :after, *(args << options), &block)
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end
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end
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end
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end
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